Association of Red Meat and Poultry Consumption With the Risk of Metabolic Syndrome: A Meta-Analysis of Prospective Cohort Studies

Dietary factors in relation to hypertension: a mendelian randomization study

BACKGROUND

Observational studies have elucidated the associations between dietary factors and hypertension. Nevertheless, the exploration of these relationships using Mendelian randomization remains scarce currently.

METHODS

The Mendelian randomization approach investigated the potential causal relationships between 16 dietary factors and hypertension. To achieve this, we identified genetic variants associated with these dietary factors by utilizing data from European-descent genome-wide association studies with a stringent significance threshold (P < 5 × 10 - 8). Subsequently, we obtained genetic associations with hypertension from the extensive FinnGen Study, encompassing 92,462 cases and 265,626 controls. Our primary analytical method was the inverse variance weighted method, and we also conducted assessments for heterogeneity and pleiotropy to ensure the robustness and reliability of our findings.

RESULTS

The study revealed significant associations with hypertension risk for various dietary factors. Specifically, higher weekly alcohol consumption (OR: 1.53, 95% CI: 1.19-1.96) and more frequent alcohol intake (OR: 1.20, 95% CI: 1.08-1.33) were positively correlated with an increased risk of hypertension. Likewise, increased poultry intake (OR: 3.25, 95% CI: 1.83-5.78) and beef intake (OR: 1.80, 95% CI: 1.09-2.97) were also linked to a higher risk of hypertension. Conversely, there were protective factors associated with a decreased risk of hypertension. These included consuming salad and raw vegetables, dried fruits, cheese, and cereals. It is important to note that no evidence of pleiotropy was detected, underscoring the robustness of these findings.

CONCLUSIONS

This study uncovered causal relationships between various dietary factors and hypertension risk. Specifically, alcohol consumption in terms of drinks per week and intake frequency, as well as poultry and beef intake, were causally associated with an elevated risk of hypertension. In contrast, consuming salad/raw vegetables, dried fruits, cheese, and cereals demonstrated an inverse causal association with hypertension, suggesting a potential protective effect.

Meat and meat products - a scoping review for Nordic Nutrition Recommendations 2023

Meat is not only a source of several nutrients but also a proposed risk factor for several non-communicable diseases. Here, we describe the totality of evidence for the role of meat intake for chronic disease outcomes, discuss potential mechanistic pathways, knowledge gaps, and limitations of the literature. Use of the scoping review is based on a de novo systematic review (SR) and meta-analysis on the association between poultry intake and cardiovascular disease (CVD) and type 2 diabetes (T2D), qualified SRs (as defined in the Nordic Nutrition Recommendations 2023 project) on meat intake and cancer by the World Cancer Research Fund (WCRF), the International Agency for Research on Cancer (IARC), and a systematic literature search of SRs and meta-analyses. The quality of the SRs was evaluated using a modified AMSTAR 2 tool, and the strength of evidence was evaluated based on a predefined criteria developed by the WCRF. The quality of the SRs was on average critically low. Our findings indicate that the evidence is too limited for conclusions for most of the chronic disease outcomes. However, findings from qualified SRs indicate strong evidence that processed meat increases the risk of colorectal cancer and probable evidence that red meat (unprocessed, processed, or both) increases the risk. The evidence suggests that both unprocessed red meat and processed meat (also including processed poultry meat) are probable risk factors for CVD mortality and stroke, and that total red meat and processed meat are risk factors for CHD. We found no sufficient evidence suggesting that unprocessed red meat, processed red meat, total red meat, or processed meat (including red and white meat) would be protective of any chronic disease. There was also no sufficient evidence to conclude on protective effect of poultry on any chronic diseases; effects on the risk of CVD, stroke, and T2D, to any direction, were regarded as unlikely.

The Association Between Food Quality Score (FQS) and Metabolic Syndrome Risk Factors in Overweight and Obese Individuals: A Cross-Sectional Study

Obesity and overweight pose a significant public health problem, as they are associated with an elevated risk of metabolic syndrome (MetS). Several studies have shown that diet quality is associated with the development of MetS risk factors. Analyzing dietary patterns may be more helpful in determining the relationship between eating habits and chronic diseases compared to focusing on single foods or nutrients. In this study, our objective was to evaluate the association of food quality score (FQS) with risk factors for MetS in individuals with obesity and overweight. The participants in this cross-sectional study were 340 adults with overweight and obesity. Participants' food intake was measured using a Food Frequency Questionnaire, then the FQS was calculated. A fasting blood sample assessed serum glucose, triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol, and serum insulin levels. Fat-free mass, height, basal metabolic rate, socio-economic score, and waist-to-hip ratio significantly differed among FQS tertiles. TC, systolic and diastolic blood pressure, and fasting blood glucose were significantly lower in the highest tertile of FQS. After multivariable adjustment, our results showed that individuals in the third tertile of FQS had reduced risk of higher levels of TC (odds ratio [OR], 0.982; 95% confidence interval [CI], 0.970-0.984) and higher levels of low-density lipoprotein cholesterol (OR, 0.974; 95% CI, 0.974-0.999). Our findings demonstrate an inverse relationship between diet quality, as measured by FQS, and MetS risk factors. However, further experimental and longitudinal investigations are warranted to elucidate the causal nature of this association.

Structuring meat analogs by citrus fiber with reduced salt intake

In this study, we investigated the effect of addition of citrus fiber (CF; 5% and 10%, which consists mainly of soluble pectin and insoluble cellulose) on physical properties and microstructure of meat analogs based on soy protein isolate and wheat gluten using high-moisture extrusion. Layered structure or microstructure of meat analogs was observed by scanning electron microscope and confocal laser scanning microscope. Compared to the control (without CF), meat analogs with CF addition showed disorder layered microstructure, which was interconnected with smaller fibers. Rheological measurements (strain sweep and frequency sweep) show that the incorporation of CF resulted in meat analogs with softer texture. The moisture content of meat analogs increased significantly upon the addition of CF, which was also correlated with juiciness. Sensory evaluation and dynamic salt release results confirm that the saltiness of meat analogs with CF addition was enhanced due to the structural changes of phase-separated structures, achieving salt reduction by 20% and showing a saltiness similar to the control sample. This research provides a novel approach to modulate the saltiness perception of meat analogs by modifying the phase separation of protein/polysaccharides. PRACTICAL APPLICATION: Citrus fiber is added to the plant protein matrix to prepare meat analogs with high moisture content and enhanced saltiness perception via modifying the phase separation of protein/polysaccharides. This work provided a potential target for the meat industry to produce the meat analogs with less salt intake. Further research can be conducted using modified fibrous or inner structure of meat analogs to improve its quality.

Red/processed meat consumption and non-cancer-related outcomes in humans: umbrella review

The associations of red/processed meat consumption and cancer-related health outcomes have been well discussed. The umbrella review aimed to summarise the associations of red/processed meat consumption and various non-cancer-related outcomes in humans. We systematically searched the systematic reviews and meta-analyses of associations between red/processed meat intake and health outcomes from PubMed, Embase, Web of Science and the Cochrane Library databases. The umbrella review has been registered in PROSPERO (CRD 42021218568). A total of 40 meta-analyses were included. High consumption of red meat, particularly processed meat, was associated with a higher risk of all-cause mortality, CVD and metabolic outcomes. Dose-response analysis revealed that an additional 100 g/d red meat intake was positively associated with a 17 % increased risk of type 2 diabetes mellitus (T2DM), 15 % increased risk of CHD, 14 % of hypertension and 12 % of stroke. The highest dose-response/50 g increase in processed meat consumption at 95 % confident levels was 1·37, 95 % CI (1·22, 1·55) for T2DM, 1·27, 95 % CI (1·09, 1·49) for CHD, 1·17, 95 % CI (1·02, 1·34) for stroke, 1·15, 95 % CI (1·11, 1·19) for all-cause mortality and 1·08, 95 % CI (1·02, 1·14) for heart failure. In addition, red/processed meat intake was associated with several other health-related outcomes. Red and processed meat consumption seems to be more harmful than beneficial to human health in this umbrella review. It is necessary to take the impacts of red/processed meat consumption on non-cancer-related outcomes into consideration when developing new dietary guidelines, which will be of great public health importance. However, more additional randomised controlled trials are warranted to clarify the causality.

High adherence to the Mediterranean diet and Alternative Healthy Eating Index are associated with reduced odds of metabolic syndrome and its components in participants of the ORISCAV-LUX2 study

Background

Metabolic syndrome (MetS) is a major risk factor for cardiometabolic complications. Certain dietary patterns play a pivotal role in improving MetS components. The aim of this investigation was to study associations between the Mediterranean Diet Score (MDS) and the Alternative Healthy Eating Index (AHEI) and the odds of MetS and its components in adults living in Luxembourg.

Methods

Data from 1,404 adults participating in the cross-sectional ORISCAV-LUX2 study were analyzed by a self-reported questionnaire, anthropometric measures, a food frequency questionnaire (174 items), and blood/urine samples.

Results

A significant association of dietary indices and MetS was not found except when expressing MetS as a score (continuous variable, log-transformed), based on the weighting of compounds using exploratory factor analysis with the MDS (β = -0.118, 95% CI: -0.346, -0.120) and AHEI (β = -0.133, 95% CI: -0.059, -0.019). Fully adjusted linear regression models further showed significant inverse associations between components of MetS and MDS (all as log-transformed variables), including body mass index (BMI) (β = -0.0067, 95% CI: -0.0099, -0.0036), waist-circumference (WC) (β = -0.0048, 95% CI: -0.0072, -0.0024), systolic blood pressure (SBP) (β = -0.0038, 95% CI: -0.0061, -0.0016), and diastolic blood pressure (DBP) (β = -0.0035, 95% CI: -0.0060, -0.0009). Similarly, significant inverse associations between AHEI and components of MetS (log-transformed) included BMI (β = -0.0001, 95% CI: -0.0016, -0.0002), WC (β = -0.0007, 95% CI: -0.0011, -0.0002), SBP (β = -0.0006, 95% CI: -0.0010, -0.0002), and DBP (β = -0.0006, 95% CI: -0.0011, -0.0001).

Conclusion

Higher adherence to a Mediterranean diet and following healthy eating guidelines were associated with reduced odds of MetS and several of its components in Luxembourgish residents, highlighting that balanced and healthy eating patterns are a crucial cornerstone in the fight against MetS.

Fasting-Mimicking Diet Reduces Trimethylamine N-Oxide Levels and Improves Serum Biochemical Parameters in Healthy Volunteers

Elevated plasma levels of trimethylamine N-oxide (TMAO) have been proposed as a diet-derived biomarker of cardiometabolic disease risk. Caloric restriction is the most common dietary intervention used to improve cardiometabolic health; however, novel trends suggest a fasting-mimicking diet (FMD) as a more feasible alternative. FMD is a variation of intermittent fasting, based on caloric restriction and limitation of protein sources of animal origin, applied in daily cycles during a 5-day period. As TMAO is intensively produced by gut microbiota after the consumption of animal-derived products, we aim to investigate whether a 5-day FMD affects plasma TMAO levels and markers of metabolic health. To investigate whether an increase in vegetable intake possesses similar effects on TMAO levels and metabolic parameters, healthy volunteers (n = 24) were subjected to a 5-day FMD and 19 volunteers served as a reference group (VEG). This group of volunteers consumed an additional four servings of vegetables per day, but otherwise stayed on their usual diet. FMD resulted in a twofold decrease in plasma TMAO levels, which was not evident in the volunteers from the VEG group. Moreover, FMD led to a weight loss of 2.8 ± 0.2 kg and a subsequent reduction in BMI compared to baseline. The FMD group exhibited a significant elevation in plasma ketone bodies (14-fold compared to baseline) and a decrease in IGF-1 levels by 37 ± 8 ng/mL. Since fasting glucose and C-peptide levels decreased, all volunteers in the FMD group showed improved insulin sensitivity and a decreased HOMA-IR index. In contrast, in the VEG group, only a slight reduction in plasma levels of fasting glucose and triglycerides was noted. In conclusion, we show that FMD is a viable strategy to reduce plasma levels of TMAO by limiting caloric intake and animal-derived protein consumption. The reduction in the level of TMAO could be an additional benefit of FMD, leading to a reduced risk of cardiometabolic diseases.

Associations of the Dietary Iron, Copper, and Selenium Level With Metabolic Syndrome: A Meta-Analysis of Observational Studies

Background

Epidemiological studies have investigated the associations of dietary iron, copper, and selenium level with metabolic syndrome (MetS). However, their results are conflicting. This meta-analysis of observational study was, therefore, employed to investigate the associations above.

Methods

A comprehensive literature search was employed using PubMed, Web of Science, Embase, and Scopus database up to October 2021 (no restriction was set for the initiate time). The pooled relative risk (RR) of MetS for the highest vs. lowest dietary iron, copper, and selenium level was estimated, respectively.

Results

A total of 14 observational studies (55,131 participants) were identified as meeting the inclusion criteria. Specifically, 7 studies were related to the dietary iron level. The overall multivariable adjusted RR demonstrated that the dietary iron level was positively associated with MetS (RR = 1.27, 95% CI: 1.12–1.44; p &lt; 0.001). With regard to the dietary copper level, 7 studies were included for meta-analysis. The overall multivariable adjusted RR showed that the dietary copper level was inversely associated with MetS (RR = 0.85, 95% CI: 0.78–0.93; p &lt; 0.001). In addition, 4 studies were specified for the dietary selenium level. The overall multivariable adjusted RR indicated that the dietary selenium level was inversely associated with MetS (RR = 0.77, 95% CI: 0.63–0.95; p = 0.01) as well.

Conclusion

Our results suggest that the dietary iron level is positively associated with MetS, whereas a negative association between the dietary copper and selenium level and MetS is obtained. Further large well-designed prospective cohort studies are warranted to elaborate on the issues examined in this study.

Relationship between Egg Consumption and Metabolic Syndrome. A Meta-Analysis of Observational Studies

OBJECTIVES

Aims: To explore the association between egg consumption and metabolic syndrome (MetS) in the adult population.

METHODS

The PubMed, Web of Science and Embase electronic databases were searched up to December 2021 for observational studies on the association between egg consumption and MetS in the adult population. The pooled relative risk (RR) of MetS for the highest versus lowest category of egg consumption, and the standard mean difference (SMD) of egg consumption for MetS versus control subjects were calculated. Egg consumption was assessed by a food-frequency questionnaire (FFQ) and the 24-hour recall method. The criteria for MetS were National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III), International Diabetes Federation (IDF), Joint Interim Statement (JIS) and American Heart Association (AHA).

RESULTS

A total of 19 articles with 20 observational studies (331667 participants) were included in this meta-analysis. The overall multivariable adjusted RR (18 studies included) demonstrated that higher egg consumption was associated with a lower probability of having MetS (RR=0.92, 95%CI: 0.88 to 0.96; P<0.001). Subgroup analysis confirmed these findings in cross-sectional studies (RR=0.91, 95% CI: 0.88 to 0.95; P<0.001), studies that used the NCEP ATP III criteria (RR=0.94, 95% CI: 0.89 to 0.99; P=0.02), Asia (RR=0.92, 95% CI: 0.86 to 0.99; P=0.02), studies with samples sizes >5000 (RR=0.92, 95% CI: 0.86 to 0.96; P<0.001), studies that adjusted body mass index (BMI) (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) and energy intake (RR=0.89, 95% CI: 0.83 to 0.94; P<0.001) and high-quality studies (RR=0.91, 95% CI: 0.88 to 0.95; P<0.001). Moreover, the overall combined SMD (5 studies included) showed that the level of egg consumption in subjects with MetS was also lower than that in control subjects. (SMD=-0.22, 95% CI: -0.25 to -0.20; P<0.001). Sensitivity analysis demonstrated that this finding only existed in studies with samples sizes >5000 (SMD=-0.21, 95% CI: -0.29 to -0.12; P<0.001) and high-quality studies (SMD=-0.23, 95% CI: -0.26 to -0.20; P<0.001).

CONCLUSION

Our results suggest that higher egg consumption is associated with a lower probability of having MetS in the adult population. However, due to the limited evidence, more global well-designed prospective cohort studies are still needed.

Associations of Serum Folate and Holotranscobalamin with Cardiometabolic Risk Factors in Rural and Urban Cameroon

A low intake of fruit and vegetables and a high intake of meat are associated with higher cardiometabolic disease risk; however much prior research has relied on subjective methods for dietary assessment and focused on Western populations. We aimed to investigate the association of blood folate as an objective marker of fruit and vegetable intake and holotranscobalamin (holoTC) as a marker of animal-sourced food intake with cardiometabolic risk factors. We conducted a population-based cross-sectional study on 578 adults (mean ± SD age = 38.2 ± 8.6 years; 64% women). The primary outcome was a continuous metabolic syndrome score. The median serum folate was 12.9 (IQR: 8.6–20.5) nmol/L and the mean holoTC was 75 (SD: 34.3) pmol/L. Rural residents demonstrated higher serum folate concentrations (15.9 (9.8–25.9) nmol/L) than urban residents (11.3 (7.9–15.8) nmol/L), but lower holoTC concentrations (rural: 69.8 (32.9) pmol/L; urban: 79.8 (34.9)) pmol/L, p < 0.001 for both comparisons. There was an inverse association between serum folate and metabolic syndrome score by −0.20 in the z-score (95% CI, −0.38 to −0.02) per 10.8 (1 SD) of folate) in a model adjusted for socio-demographic factors, smoking status, alcohol intake, BMI, and physical activity. HoloTC was positively associated with the metabolic syndrome score in unadjusted analysis (0.33 (95% CI, 0.10 to 0.56)) but became non-significant (0.17 (−0.05 to 0.39)) after adjusting for socio-demographic and behavioural characteristics. In conclusion, serum folate and holoTC were associated with the metabolic syndrome score in opposite directions. The positive association between serum holoTC and the metabolic syndrome score was partly dependent on sociodemographic characteristics. These findings suggest that, based on these biomarkers reflecting dietary intakes, public health approaches promoting a higher intake of fruit and vegetables may lower cardiometabolic risk factors in this population.

Associations of Dietary and Circulating Vitamin E Level With Metabolic Syndrome. A Meta-Analysis of Observational Studies

Objective: The associations of dietary and circulating vitamin E level with metabolic syndrome (MetS) remains conflicting. This meta-analysis of observational study was therefore employed to investigate the issue above.

Methods: The PubMed, Web of Science and Embase database were searched up to April 2021. The observational studies on the associations of dietary and circulating vitamin E level with MetS were specified. The pooled relative risk (RR) of MetS for the highest vs. lowest dietary and circulating vitamin E level, and the standard mean difference (SMD) of dietary and circulating vitamin E level for MetS vs. control subjects, were calculated.

Results: A total of 25 observational studies with 51,276 participants, were included in this meta-analysis. The overall multi-variable adjusted RR demonstrated that the dietary vitamin E level was inversely associated with MetS (RR = 0.92, 95%CI: 0.85–1.00; P = 0.044). In addition, the dietary vitamin E level in MetS was also lower than that in control subjects according to the overall combined SMD (SMD = −0.08, 95%CI: −0.14 to −0.02; P = 0.024). On the other hand, the overall multi-variable adjusted RR showed no significant relationship between the circulating vitamin E level and MetS (RR = 1.46, 95%CI: 0.85–2.48; P = 0.17). However, the circulating vitamin E level in MetS was lower than that in control subjects according to the overall combined SMD (SMD = −0.58, 95%CI: −1.04 to −0.13; P = 0.013).

Conclusions: The results of this meta-analysis suggest that the dietary vitamin E level is inversely associated with MetS. On the other hand, current evidence is still insufficient to conclude a relationship between the circulating vitamin E level and MetS. More well-designed prospective cohort studies are needed to address the issues further.